Technical Field
Example embodiments generally relate to a high-pass filter circuit and a band-pass filter circuit.
Background Art
In recent years, for the purpose of adding energy-saving or other convenient functions to household electrical appliances, the development of various kinds of sensors integrated into a semiconductor integrated circuit such as an infrared sensor, an image sensor, and a temperature sensor is actively carried out. As signals output from some of these sensors are minute and at low velocity, the amplitude of these signals needs to be amplified by an amplifier circuit in a subsequent stage. However, if the signals including direct-current components are amplified, the direct-current components are also amplified and the alternating-current signal components are not sufficiently amplified. For this reason, it is desired that the output signals from a sensor be amplified upon passing through a high-pass filter circuit.